Feeding calves vitamin C
It works some of the time, but veterinarians remain skeptical
BY DON STONEMAN
The practice of feeding vitamin C to newborn calves has found some success on the Prairies, but it's hard to find an animal scientist or veterinarian who favours it.While many people take vitamin C to prevent colds in winter, the 30-year-old research behind the practice remains controversial to this day. The same goes for feeding vitamin C to newborn calves to prevent scours.
OMAFRA veterinarian Rob Tremblay has read some of the research supporting vitamin C and notes that some studies showed positive results, while other studies showed no benefit. He remains skeptical, partially because the background treatment of the calves is sometimes unclear and could skew results.
"If animals are deprived of vitamin C in the ration, any supplementation will look good," Tremblay says. On the other hand, dairy calves fed a milk replacer ration, for example, may be getting enough vitamin C through the ration.
With studies showing vitamin C is effective only some of the time, "don't make it a pillar of your husbandry," Tremblay advises. A vitamin C supplement may help calves that don't get colostrum, but calves are likely better off if they get the first dose from a mother's udder, he says.
"It's not the sort of management practice I would reach for right away," says Ann Godkin, another OMAFRA veterinarian. Calves will also be better off if they are born in a dry location from mothers with a good body condition score. Those factors are likely more important than any gain you would accomplish from feeding vitamin C, she says.
If vitamin C is administered it should be given in the first few weeks after birth.
Among the issues not addressed in the research Tremblay has seen is whether diarrhea interferes with a calf's ability to take up vitamin C. He wonders if calves with diarrhea have a greater need for vitamin C.
Ray Jones, Alberta-based nutritional service manager for Roche Vitamins, says it is apparent that vitamin C can work with vitamin E to boost ruminants' immune response. Vitamin E has widely accepted benefits for young calves: An injection shortly after birth is common practice in well-managed beef cow herds.
Jones explains that vitamins E and C often work together. Vitamin E helps macrophages work. Macrophages are the body's response to foreign invaders such as viruses. But as the macrophages engulf viruses and bacteria, the vitamin E is weakened. Vitamin C revives the vitamin E.
Jones likens vitamin E to the deflector shields on the Enterprise, the starship in the popular Star Trek television series.
Jones refuses to recommend vitamin C as a preventative treatment for disease in young calves. The trouble with anecdotal evidence describing on-farm cures is that the farmer typically treats all calves. It's not clear if the disease was still present in the herd.
"Maybe [the disease] ran its course" in the calves at the same time as the treatment was initiated, Jones says.
He notes that a gram of vitamin C - two 500 milligram pills - probably costs 10 cents, so a daily one gram dose isn't a major input cost. Typically, studies involved a daily dose to a calf of four grams over three days.
Regular vitamin C fed to older animals is a waste, because it is broken down in their rumens, Jones says. He has been telling farmers not to bother feeding vitamin C to 500 and 600 pound calves to prevent shipping fever.
Other beef researchers are also leery of giving vitamin C too much credit when it comes to curing viral pneumonia or diarrhea.
Tom Hamilton, a beef researcher at New Liskeard, points out that some research shows sick calves have lower levels of vitamin C. He thinks this may be linked to a sick animal's lower feed intake or because the disease has knocked down the animal's vitamin C level.
When vitamin C is supplemented, "You may actually be seeing a response to the correction of a deficiency, rather than a boost from an extra dose," Hamilton says.
© copyright 1999 Agricultural Publishing Company Limited.
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Manure scientists seek sweet smell success
By Owen Roberts
Many of the 13 different compounds that give pig manure its distinctly offensive bouquet even sound like they stink.Imagine a whiff of 3-methyl butanoic acid, a waft of 4-ethyl phenol, a sniff of ammonia, a snort of skatole. Whew! No wonder farmers' neighbours are fuming. In fact, the Canadian Pork Council (CPC) says that, besides price, manure odour is one of the pork industry's main growth-limiting factors.
But if a team of University of Guelph animal scientists has its way with pig manure, offended civilians will soon be closer to aromatic bliss. With support from CPC and various industry partners including Elanco Animal Health and Hedley Technologies, the team is starting a two-year project to manipulate hindgut (large intestine) fermentation in pigs. Team members think they can reduce the excretion of the odour-causing compounds mentioned earlier - plus 150 or so other volatile substances found in pig manure - and help make hog farms less of a rural pariah.
"We live in a country with all the advantages for a pork industry, such as cheap land and grain and superb genetics," says team member Trevor Smith, of the university's Department of Animal and Poultry Science. "But if there's no accord on the odour issue and hog farms can't grow, the industry can't expand. Then we're in real trouble."
Previous research designed to curb odour has concentrated mainly on controlling nitrogen excretion. It's a legitimate approach, because many of the odour-causing compounds in pig manure are related to the pig's protein (nitrogen) utilization. But this hindgut manipulation project takes odour control one step further. It integrates the animal feed and metabolism expertise of Smith and colleagues Kees de Lange and Jim Squires with those of environmental physiologist Ming Fan, whose animal and poultry science posting is sponsored by Ontario Pork.
Together, the researchers are looking at ways to change the troublesome compounds. First, in the pigs' feed they're introducing binding agents, non-digestible substances designed to tie up the compounds and keep them intact so they don't get absorbed. "If they stay bound they're not released into the air and don't smell when they're excreted," says Smith.
The researchers are also trying to manipulate gut acidity. Like all animals, pigs have microbes in their gut that help digest food. Microbes' activity can be influenced by changing the acidity in the gut. There's promising evidence of advances in this area. For example, a recent study in the Netherlands suggested ammonia emissions in pig barns can be cut by a whopping 40 per cent when certain organic acids are added to growing-finishing pig diets. Another study in Denmark showed that making the gut more alkaline - which can be done simply by feeding bicarbonate - lowered the production of skatole, the compound blamed for giving boar taint meat its unpleasant smell.
The Guelph research team thinks fibre may also play a role in reducing odour. Other studies have reported that increased fibre cut skatole levels in both blood and feces. So the researchers are investigating various widely available fibre sources for their affect on odour.
Finally, they're going to examine how certain feed additives affect the microbial environment in the pig gut. Some are believed to prevent intestinal microbes from breaking down an important amino acid called tryptophan and increasing levels of skatole. As well, they alter the hindgut production of certain volatile fatty acids, likewise known to contribute to odour.
Ultimately, part of the project's success will be measured by noses...but not necessarily human ones. Squires is working to perfect an "electronic" nose consisting of finely-tuned sensors that can sniff out unacceptable manure odours.
Owen Roberts heads research communications for the University of Guelph
© copyright 1999 Agricultural Publishing Company Limited.
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Turkey processors tie knot
Maple Leaf Poultry and Cold Springs Farm marry processing operations under one name
BY CHRISTINA SELBY
Cost efficiency makes for strange bedfellows. In this case, competing turkey processors Maple Leaf Poultry and Cold Springs Farm have formed a joint venture to combine processing operations under a new company, Thames Valley Processors.While it may look like an "elephant and ant" getting together, Brian Cram, executive vice-president of Cold Springs, says the Thamesford-based company is slightly larger than Maple Leaf in turkey processing.
Maple Leaf's Walkerton plant will be closed, costing 293 unionized jobs, and the company's processing will move to Cold Springs' non-union Thamesford plant. "This is a 50-50 venture strictly on slaughter and boning facilities and doesn't include other Cold Springs operations," says Cram.
"We will maintain the land and building and lease them to Thames Valley; equipment will be held jointly." The Cold Springs facility was chosen over the Walkerton plant because it has undergone considerable renovation and equipment upgrading in the last few years, Cram says.
Cram and Maple Leaf Poultry vice-president of operations Kevin Golding hope the Thamesford plant will be able to handle the increased number of birds - 15 to 17 million kgs a year, estimates Golding - on a single shift. "We anticipate maintaining staff levels," Cram says.
Investing in automation is a "Catch 22," Cram says. "If you don't use the faster speed lines, you're falling behind."
Production levels also have to keep pace. Cold Springs fought hard for increased allocation in the tom - eight kg or more - category, Cram says. JoAnn Crane, general manager of the Ontario Turkey Producers' Marketing Board, says Canadian turkey quota has increased by eight million kgsfor the 1998-99 quota period, with Ontario getting about 42 per cent.
Cram and Golding say both plants were running below capacity. Cram says the Thamesford plant can process about 2,500 small broilers an hour. Says Golding: "The bottom line was that it got difficult to provide work on a regular basis. We had people on lay-off and the situation couldn't continue."
The supply management system of turkey allocation means that there are a finite number of birds available for processing, says Cram. Increasing margins means increasing efficiencies.
Amalgamated processing will mean lower costs for both companies and could lead to increased employment in the long term. Golding says Walkerton employees will be given "full consideration" should any jobs become available at the Thamesford plant or other Maple Leaf operations: "We're hoping to place as many people as possible."
There are no plans for the Walkerton facility at this point, says Golding. As of April 5, the plant becomes the property of Thames Valley, so its future will be decided by the new company.
Neither company will be sacrificing market identity in the name of economizing, says Cram. Both companies' fresh and frozen products will continue to be produced under Maple Leaf and Cold Springs banners. Separate sales, marketing and distribution sections will help maintain separate revenue streams.
Cram says the joint venture reflects the future for the Ontario turkey industry: "Pretty much all processors are talking to others" looking for a deal such as theirs. Industry consolidation is "inevitable," he says.
Crane says that's fair comment on the industry. "It's always been said that there's too much shackle space in Ontario," she says.
© copyright 1999 Agricultural Publishing Company Limited.
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